Answer:
≈ 8.07 mg
Step-by-step explanation:
Given
f(x) = 12
Substitute x = 1 into f(x) , that is
f(2) = 12(0.82)² = 12 ×0.6724 ≈ 8.07 mg
There is actually 2 ways to solve this, I will show you both.
The first is obvious, solve for x in the first one, and plug it into the 2nd one and get the answer
4x + 7 = 12
4x = 5
x = 
8(
) + 3
2 * 5 + 3
10 + 3
13
The 2nd option is to manipulate the 4x + 7 to be 8x + 3
4x + 7 = 12
start by moving the 7 over
4x = 5
multiply both sides by 2
8x = 10
and add 3 to both sides
8x + 3 = 13
Ralph is 3 years old
Casey is 18 years old
Step-by-step explanation:
Let the age of Ralph be x
Then Casey is 6 times as old as Ralph will be 6x
In two years
Ralph =x+2
Casey=6x+2 ⇒ 4(x+2)
Equate the two equations for Casey as
6x+2 = 4x+8
6x-4x=8-2
2x=6
x=6/2= 3
Current age;
Ralph= x= 3 years old
Casey=6x = 6*3= 18 years
Learn More
Forming expressions and solving equations;brainly.com/question/1280754
Keywords :six, times, years
#LearnwithBrainly
Answer:
A
Step-by-step explanation:
In order to compare all three numbers, you must change them all to have the same form, either all decimal form, all fraction, or all percentages.
The easiest ways to compare are decimal and percentage, as they're practically the same thing. For simplicities sake, though, let's turn all the numbers into decimal.
Since 0.85 is already in decimal form, leave it as it is.
3/4 can be turned into a decimal by putting it into a calculator, but intuitively you should know that it's 0.75. If you don't know a fraction intuitively, you just need to make the fraction into a multiple of denominator 100 and take the numerator. For example:

Numerator is 75.0, now simply move the decimal place up to to get the decimal form 0.75.
91% can be changed into a decimal by moving the decimal place left 2 places. 91.0% turns into 0.91.
Now that you can see the numbers, just rearrange them from least to greatest
0.75<0.85<0.91
equal to A